https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114190
--- Comment #6 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:1157d5de35b41eabe5ee51d532224864173c37bd commit r14-9329-g1157d5de35b41eabe5ee51d532224864173c37bd Author: Jakub Jelinek <ja...@redhat.com> Date: Wed Mar 6 09:35:37 2024 +0100 i386: Fix up the vzeroupper REG_DEAD/REG_UNUSED note workaround [PR114190] When writing the rest_of_handle_insert_vzeroupper workaround to manually remove all the REG_DEAD/REG_UNUSED notes from the IL, I've missed that there is a df_analyze () call right after it and that the problems added earlier in the pass, like df_note_add_problem () done during mode switching, doesn't affect just the next df_analyze () call right after it, but all other df_analyze () calls until the end of the current pass where df_finish_pass removes the optional problems. So, as can be seen on the following patch, the workaround doesn't actually work there, because while rest_of_handle_insert_vzeroupper carefully removes all REG_DEAD/REG_UNUSED notes, the df_analyze () call at the end of the function immediately adds them in again (so, I must say I have no idea why the workaround worked on the earlier testcases). Now, I could move the df_analyze () call just before the REG_DEAD/REG_UNUSED note removal loop, but I think the following patch is better, because the df_analyze () call doesn't have to recompute the problem when we don't care about it and will actively strip all traces of it away. 2024-03-06 Jakub Jelinek <ja...@redhat.com> PR rtl-optimization/114190 * config/i386/i386-features.cc (rest_of_handle_insert_vzeroupper): Call df_remove_problem for df_note before calling df_analyze. * gcc.target/i386/avx-pr114190.c: New test.
